1. Field of the Disclosure
The present invention relates to liquid crystal display devices, and more particularly, to device and method for driving a liquid crystal display device, in which a detection factor for a defective display pattern, and a detection stop factor for the defective display pattern are changeably set for preventing defective display and a poor picture quality caused by frequent pattern change from taking place.
2. Discussion of the Related Art
Recently, as flat panel display devices for use in personal computers, personal digital assistants, and monitors for various information apparatuses, the liquid crystal display devices, light emitting display devices, plasma display panels, field emission display devices, and so on are under development.
Of above flat panel display devices, the liquid crystal display devices are used widely owing to low power driving, and a good picture quality. The liquid crystal display device displays a picture by controlling a light transmissivity of liquid crystals by using an electric field. For this, the liquid crystal display device is provided with a liquid crystal display panel having a plurality of pixel cells, a backlight unit for directing a light to the liquid crystal display panel, and a driving circuit for driving the pixel cells. For driving sub-pixels on the liquid crystal display panel in the liquid crystal display device, inversion driving systems, such as a frame inversion system, a line inversion system, dot inversion system, and so on are used. Of the inversion driving systems, the dot inversion system provides a picture of a picture quality better than the frame and line inversion systems.
However, even if an image is displayed by the dot inversion system, in a case an image of a particular pattern, for an example, a vertical line pattern of a gray background, or a horizontal line pattern having a high contrast, is displayed, the picture quality is poor due to distortion of a common voltage, causing smear on a display screen or the like.
Consequently, in the related art, devices and methods are studied, in which predefined defective display patterns which cause smear are detected at the time of a video data input, and the inversion system is changed if the smear causing pattern is detected. A method for detecting the smear causing pattern developed the most in the related art is a method for setting defective display pattern information for detecting the smear causing pattern, and comparing the defective display pattern information set thus to an image data.
However, the related art method for detecting a defective display pattern, for an example, the smear causing pattern, develops defective picture display due to frequent change of the inversion system in a case changes of brightness of the picture and pattern are great. In other words, in the related art, the defective display, such as flickering of the screen before or after a threshold value caused by frequent change of a preset pattern inclusion ratio, for an example, a pattern perception (on/off) of picture pattern change coming from movement of a folder window, movement of a mouse, and so on, becomes more serious.